Furnace wall construction



Patented Sept. 6, 1932 UNITED STATES PATENT OFFICE FRANK I. SHEAHAN, OFCHICAGO, ILLINOIS, ASSIGNOR TO M. H DETRICK COMPANY, F CHICAGO,ILLINOIS, A CORPORATION 0F ILLINOIS FURNACE 'WALL CONSTRUCTION Y Thisinvention relates to the construction of furnaces or heating orcombustion chambers, such as boiler furnaces, oil stills, and the like,having walls of refractory material such as fire brick.

A general object of the invention is the provision of a refractory wallconstruction in which the wall refractories are afforded definitesupport and anchorage, the supporting framework is afforded suitableprotection against injury from heat, the wall is practically proofagainst gas leakage, and the structure may be built at comparatively lowcost.

A. particular object of the invention is the provision of a constructionfuor sectional supported walls which are carried on a metallic frame,and wherein the amount of material required for the frame to support awall of 1 given weight may be very substantially reduced from thatheretofore requisite in walls of that type.

Another particular object is the provision of improved features orstructural elements in such wall construction lwhereby the advantagesindicated above may be attained.

Other and further objects of the invention will be ointed out orindicated hereinafter, or will Ee apparent to one skilled in the art lupon an understanding of the invention or its employment in practice.

For the purpose of aiding in a description of the invention, lillustrate in the accmpanying drawing forming a part of thisspecification, and hereinafter describe, certain examples ofconstruction embodying the invention. It is to be understood, however,that these are presented for purpose of illustration only, and are notto be accorded any interpretation calculated to limit the claims shortof the true and most comprehensive scope of the invention in the art.

In the drawing, v l Fig. 1 is a cross section through a portion of afurnace wall of a length, for example, of thirty feet;

Fig. 2 is a cross section on a larger scale;

Fig. 3 is a part sectional elevation on substantially line 3-3 of Fig.2;

Fig. 4 is a detail in the nature of a part sectional elevation on line 44 of Fig. 2;

Fig. 5 is a detail showing a portion of the exposed directly to themaximum furnace temperatures, it is customary to afford such walls anexternal air cooling to prevent the temperature of the wall refractoriesbeing raised to a point at which they would be rapidly destroyed byfusion or slagging. In some types of installations, however, the wallrefractories are to a Greater or less extent shielded or protected fiomthe extreme high furnace temperatures by water tubes which are arrangedwithin the furnace chamber in juxtaposition to the interior wall surfaceand form part of the boiler circulatory system. Also in some types offurnaces, petroleum stills, for example, the furnace temperatures arenot extremely high, but the function of the refractory wall is none theless important, not only in confining the furnace gases and inducingcombustion thereof, but also in effecting the desired radiation of heatto the still tubes. Refractory walls for furnaces of this type maybemade somewhat thinner than is requisite for furnaces operating at hightemperatures.

The present invention provides a construction lfor a frame supportedsectional wall which possesses all of the advantages of flexibility,facility of installation and repair, durability and interchangeabilityof parts, and yet which may be constructed and maintained at very lowcost, as compared to the cost of frame supported sectional wallsgenerally. This vhighly important result is obtained primarily byimprovements in the construction and assembly of the elements whichsupport and an'chor the wall refractories, by virtue of which it ispossible to obtain the requisite stii'ness and 4stability 0f the framestructure with appreciably less ma- 5 terial than heretofore regarded asnecessary to ive the proper factor of safety.

rhe nature of the invention will be most quickly understood byreferenceto the illustrative embodiments shown in the' drawing. Let Fig.1 be regarded as vrepresenting a T stretch of wall of considerable)extent, say of a length of thirty feet, the same forming a part of afurnace or combustion chamber such as a radiant petroleum still, forexample. Along the wall, at appropriate intervals, are

arranged the frame columns 10, suitably supported in upright position.These form-the lprincipal supporting members of the wall structure. Asillustrated, for the purpose of demonstratin one of the importantadvantages attaine by the presentinvention, these column members,assuming this section of -wall to be thirty feet in length, are placedat intervals of seven and one-half feet. For

convenience in the manufacture and assembly and interchangeability ofparts ofy the structure, itis desirable that the spacing of thesecolumns be uniform. Fixed to and supported by these column members arestretcher members 11, which extend horizontally from one cglumn toanother. As best seen in Fig. 3, these stretcher members have upperianges-lla and lower flanges 1 1" which are parallel and referably liein the same plane, and which anges are spaced apartby axconsiderableinterval that is spanned by av web portion llc. These stretcher membersmay be made quite economically and conveniently of three channelsections riveted vto- 40 gether in the relationshi shown. Thus 'a memberis providedwhic is reversible, itsA upper and lower halves beingidentical. The I,length of the stretcher members is suiicient to extendfrom center' to center of adjacent columns, and outer corner portions ofthe upper and lower channel members may be notched out to accommodatethe column lianges. They are attached to the 4ianges of the col- \umnsby bolts passing through 'the webs 11. Thus horizontal series of thestretcher members may be mountedon the columns in par-` allelrelationship one above another. The stretcher members constructed asshown have very decided stiffness across both their axes, for the amountof metal whichthey contain, 'and thus may be depended upon to'supportextensive spans of the suspended wall without appreciable deflectioneither inwardly, outwardly or downwardly. This permits the spacing ofthe column members by substantial intervals, thus minimizing the numberof such column members requisite for a given extent of wall. c

The refractory wall is of sectional con- 25 struction, the sectionsbeing supported independentl one above another so that the weight o oneis not imposed on those below it, expansion of respectlve sections isaccommodated, and sections or parts thereof may be removed and replacedindependently. Forsupporting and anchoring the wall refractories, tileretaining brackets 0r hangers distance below the hook arm. These tilere-` taining hangers or brackets are preferably made of cast iron. Thelength and relationship o f the hook arm 12c and spacing prol jection12d are such that when the former is enga ed with ,the upper flange 11*Lof a stretc er member, the spacing projection`12d will engage the outerface of the lower flange 11". Thus the tile retaining hangers may esuspended in series on the respective stretcher members, with thehangers occupying a vertical position and with the body portion spacedaway from the stretcher members.

The refractory tiles 14 and 15 are supported on the hangers with thelateral faces of tiles on juxtaposed hangers in abutment. These tilesare generally of rectangular form with T-sh'aped slots at their outerends, which slots accommodate the body port-ion 12 and. the flanges 12bo f the hangers with suiiicient clearanceto allow a slight mobility ofthe tiles with respect thereto. Thetiles are slid;

onto the upper ends of the ilanges and body ortion and are retainedagainst dislodgment y the engagement `of the flanges in their slots. Thetiles 14, which are at the bottom of the hangers, have .dependingportions which extend across the inner margins of the shelves 12L forsealing cooperation with refractories on the subjacent section. Thevertical spacing of the stretcher members, and hence of the hangers, issuch that there is suiiicient space between thehangers to permit theinsertion and removal of tiles 14 and 15 in any section withoutdisturbing the' superjacent section. The upper course -of each sectionis formed of the tiles 16 which are considerably smaller than the tiles15. lhe tiles 16 have an u standing portion ad,- jacent their outer en sadapted for overlappmg cooperation with the depending por- ,tions' ofthe tiles 14 and 15 of the superjacent section to form a sliding joint,and an expansionspace isleft between the course of tiles 16 and thetiles 14 and brackets of vthe superjacent section to allow for verticalexpansion of the lower section without imposmg strains on therefractories in the superjacent section. This expansionA space is isosuch as a mixture of fire clay and asbestos. The tiles 16 havetransverse notches in their lower faces adapted to align with the headportion o f the T-shaped slots of the tiles 15, and may be anchored inplace by means of anchor castings 17 which fit into the slots of thetiles and extend to the sides thereof and register in the slots of thetiles 16.

Y be formed with laterally offset shoulders and depressions, asillustrated in Fig. 6, in order to form atortuous joint between them andthus increase the tightness of the seal against gas leakage. ln order toincrease the tightness of the joint between laterally abutting tiles 14and 15, those tiles may be formed with grooves in their side margins, asof the form shown in Fig. 2, and sealing keys or plugs'l inserted in theopenings aorded by these grooves. After a number of the courses of'tiles 14 and 15 have been laid, these plugs or keys may be inserted fromthe top after being doped with fluid fire clay. ln various installationsthis matter of tight joints is of importance, both as a measure forprotecting the external metal work or" the frame and to prevent theejection of gas into the air space outside the refractory wal on theoccasion of explosions which are likely to occur periodically when thefurnace is fired with liquid or pulverized fuel'sprayed into thecombustion chamber. Since the air circulated in such air space isusually brought back into the combustion chamber with the fuel to serveas primary combustion air, it is of importance that it be as freeas'possible from inert or partially consumed combustion gases. In orderto enclose the air circulating space at the outer side, so as to formcirculating ducts, an externalsheathing 19 of suitable material, such asrefractory insulating board, may be attached by bolts to the outerflanges of the column members 10.

It will be observed that by virtue of this construction the wall tilesare all deinitely anchored in the wall so as to prevent-their shiftinginwardly into contact with tubes 2O which may be arranged in associationwith the inner wall surface, and to maintain the proper relationship ofsuch surface to the tubes to obtain the desired heat radiating effectsupon the latter. Although thus anchored against dislodgment, therefractories have a desirable freedom of movement perf mitting theiradjustment relative to one another to accommodate expansion, and therespective sections have likewise a, desirable latitude for expansion.At the same time the constructionmaintains tight joints between all ofthe abuttin refractories'.

It will be observed t at although advantage is gained by thisconstruction in permitting the overall thickness of the wall from theinterior surface to outside' of the sheathing 19 to e limited, noneofthe supporting steel work is in direct contact with the wallrefractories or with other members which are in contact with therefractories. The actual heat conductive connection between thestretcher members and the wall hangers is very small, consisting only ofthe limited areas of contact between the hooks 12c and projections 12dof the hangers and the stretcher members 11. Excepting for these verysmall areas of contact, the stretcher members are completely exposed tothe circulation of cooling air within the air circulating space, as arealso the column members; and although the eccentricity of the wallsections with respect to the column members is small, the latter arespaced away from the wall refractories by a distance suliicient topermit effective ventilation and cooling. This effective cooling and:minimizing of heat conduction from the refractory wall to the framemembers permits a substantial reduction in the weight of the supportingframe members.

By virtue of the construction, as pointed out above, the stretcherinembers may be fabricated from standard sections of rolled steelchannel members, and thus may be formed with Strict uniformityL ,andwith definitely. known strength, as com asted to cast members,whichusually show variations in dimensions and are likely to containconcealed air holes which render their strength a matter of conjecture.By forming the stretcher members with the bea-ring points for thehangers spaced apart vertically a substantial distance, the tortionalleverage exerted on them by the weight of the wall sections issubstantiallyl reduced and the stability of the structure is materiallyincreased.

What I claim is:

1. Furnace wallstructure comprising in combination, upright framemembers spaced apart along the furnace, a horizontally ex-4 tendingchannel member attached to adjacent upright members with its web inupright position, angle members extending along the l upper and lowersides of the channel member and attached to the flanges thereof to formtherewith a stiff stretcher member, hangers arranged at one side of thestretcher members and each having bearing engagement with the anglemembers at the upper and lower sides thereof, and refractories carriedon the hangers tof form a wall portion entirely spaced collaterally'from the upright and stretcher members.

2. Furnace wall structure comprising in combination, u right framemembers spaced alongsidethe urnace, horizontally extending channelmembers spaced apart vertically, a horizontally extending web memberattached at its upper and lower sides to the -I channel members andhaving supporting connection with the upright frame members, hangersdisposed at one side of said channel members and each having supportingengagement with both the vertically spaced ones and refractoriessupported on the hangers to form a furnace wall portion alongside thechannel members and entirely spaced therefrom. v

3. In furnace wall structure, the combination of parallel upright framemembers, a horizontal stretcher member connected to the upright membersand having portions at its ipper and lower sides disposed artly betweenand extending partly beyond) the upright members, hangers supported onsaidextending portions of the stretcher members and depending at theside of the latter, and wall refractories supported on and anchored tothe hangers with their outer faces in proximity'to but spaced from thestretcher members.

4.' In furnace wall structure, the combination of parallel upright framemembers arranged alongside the furnace, a horizontalA stretcher memberconnected tothe upright members andfhaving a web portion disposed inlavertical plane and laterally extendingv stifening portions disposedpartly between the upright members and partly beyond the v vfurnace sidethereof, hangers extending vertically alongside the stretcher membersand supported on said stifening portions, and

wall refractories supported on and anchored to the hangers with theirouter faces inproximity to but spaced from the stretcher and uprightmembers.

5. In -a furnace, a wall construction comprising, in combination,upright frame members, a stretcher member extending horizontally fromone to another of said upright frame members, said stretcher memberhaving a web portion disposed in a vertical plane and attached to theupright frame members and stifl'ening portions extending transversely ofthe web portion along its upper and lower margins, hangers extendingvertically alongside the stretcher member and supportf ed thereon incontact with its upper and lower stiifening portions, and refractoriessupported on the hangers to form. a wall portion alongside and spacedfrom thevertical frame and stretcher members.

In testimony whereof I have hereunto subscribed my name. f

' FRANK I. SHEAHAN. I

